THE poisoning of former Russian spy Sergei Skripal "will be proved" to be a Kremlin plot to assassinate a double agent, businessman Bill Browder alleged.

Dubbed Putin’s “number one enemy”, Bill Browder said the Kremlin could be behind the poisoning of former Russian spy Sergei Skripal.

Mr Browder, who was deported from Russia after attempting to expose corruption in the country, said it will be proven that Russia is to blame for the poisoning which took place on UK soil.

Sergei Skripal and his daughter collapsed at a shopping centre in Salisbury on Sunday and were rushed to hospital after being poisoned by a nerve agent.

The highly toxic substance used in the targeting of the former spy has been used in assassinations and attacks in war zones in recent years.

Getty•Channel 4

Bill Browder said Russia will "be proven" to be behind former spy poisoning

These people are not some type of super James Bond characters that didn’t leave enough clues

Bill Browder

Speaking onChannel 4 News, Mr Browder said: “It will be proved. It will be proved because these people are not as professional as you think. In the Litvinenko case, it took three tries before they actually got Litvinenko.

“They were leaving breadcrumbs of radioactive material all over the country.

“These people are not some type of super James Bond characters that didn’t leave enough clues to figure out who did what here.”

Activist Alexander Goldfarb also alleged Vladimir Putin had the “motive”andopportunity to “poison” former Russian spy Sergei Scribal in British shopping centre - in a move that could boost his political presence ahead of the Russian election.

Speaking on BBC Radio 4’s Today Programme, Mr Goldfarb said: “The Russian secret services and the regime of Mr Putin had the motive and the opportunity to do this. And they did it before. I mean, it’s only natural for any reasonable person to suspect them.”

Mr Goldfarb, a close friend of killed dissident Alexander Litvinenko, said he has a theory as to why Russia could be behind the latest alleged poisoning.

The microbiologist and activist said it is not a spy theory but instead a political move, insisting the “majority” of Russians would perceive the “poisoning” as the right thing to do as they view Putin as a leader that can “get his enemies wherever they are across the globe.”

Sergei Skripal, 66, was a retired Russian military intelligence colonel who was accused of spying for the UK since the 1990s and sentenced to 13 years in prison in 2006.

Kremlin spokesman Dmitry Peskov said: “We don’t possess any information about what could have been the cause and what this could be connected to.”

The fresh poisoning claims draw comparisons to the death of Russian dissident Alexander Litvinenko in London in 2006, where a public inquiry ruled the killing had “probably” been carried out by Putin’s administration.

The widow of Mr Litvinenko has said the news of Mr Skripal’s conditions is like “deja vu”. Marina Litvinenko told BBC Radio 4: "It's like deja vu – what happened to me 11 years ago."

"In Russia, it is still old-fashioned and old-style KGB system. It's still all the same. If there is an order to kill somebody it will happen."